Diffusion process.



J. STEWART.

DIFFUSION PROCESS.

1,189,503. APPLICATION FILED FEB. 2. I9I6- Patented 4:,

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J.STEWART.

DIFFUSION PROCESS.

APPLICATION FILED FEB-2.1916.

Patented July 4, 1916.

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JOHN STEWART, OF SALT LAKE CITY, UTAH.

DIFFUSION PROCESS.

Specification of Letters Patent.

Patented July 4, 1916.

Application filed February 2, 1916. Serial No. 75,745.

To all whom it may concern:

Be it known that 1, JOHN STEWART, a citizen of the United States, residing at Salt Lake City, in the county of Salt Lake and State of Utah, have invented certain new and useful Improvements in Diffusion Processes, of which thefollowing is a specification.

This invention relates to a diifusion process for extracting sugar from sugar beets especially, although it is applicable to the extraction of sugar or other constituents from other materials.

In my U. S. Patent, No. 7,962,597 a process is disclosed which involves reducing the material to a pulp which is passed in one direction through an elongated chamber heated throughout its whole length to different degrees at different places, the temperature being greatest at or near the inlet to said chamber, and flowing water through said pulp in the. opposite direction to the flow of the pulp, the continuity of the process being possible by reason of the pulp be ing continuously fed at one end and the spent pulp being discharged at the other, the flow of water being also continuous.

The object of the present invention is to improve the process described in said patent, especially by anew mode of treatment of the pulp as it is being subjected to the action of the water, whereby the time required for diffusion is lessened, the extraction is more perfect, the dimensions of the apparatus may be smaller, and various other mechanical advantages follow.

An important feature of the present process is that the pulp or material, while it is subjected to the action of the water, is agitated or tumbled in a rotary cylinder or vessel, and at the same time is conveyed through said vessel, which is submerged in a trough through which the water flows in a steady stream in a direction opposite to or difierent from the movement of the pulp. Preferably, the conveyor is only partly filled with the pulp, whereby the latter has space to lift and drop, and in consequence of the agitation and the movement thereof, all parts of the pulp are directly exposed to the extracting action of the water. Although it is preferable that the material be reduced to a pulp, the process may be performed on cossettes or upon other fragmentary or disintegrated beets, cane or other material.

The apparatus for performing the present process is particularly described in my pending application, No. 73,129 filed Jany 20, 1916, and will be briefly described herein, in connection with the accompanying drawings, in which 1 Figure l is a vertical sectional view of the apparatus, Fig. 2 is a plan, partly in section, and Fig. 3 is a vertical cross section.

In these drawings, 4: indicates a vertical leg into the top of which the pulp or material is introduced from a shredder or the like indicated at 19. This leg has a strainer 15 at the top communicating with a chamber 16 and an outlet 17 for the juice, the feed through the leg being controlled by a gate valve 5. Extending into the bottom part of the leg is an elongated perforated cylinder 8 on a central shaft 6, with a screw conveyer 18 of perforated metal fixed to the shaft and the cylinder, so that all rotate together. The inner end of the screw projects beyond the end of the cylinder into the foot of the leg 4, thus acting to convey the pulp from said leg into the cylinder 8 and to carry the same upwardly or outwardly through the cylinder where it is delivered into a casing 30 provided with an elevator 23 for lifting the discharged or spent material. The shaft and its connected parts are rotated by power applied to the outer end thereof.

The cylinder rotates in an inclined trough 7, upon rollers 19 therein, and through this trough water is flowed from an inlet 14, the trough being filled with water which rises in the vertical leg 41 to the outer strainer 15 and pipe 17. The water supplied by the pipe 14 will be cold, or of relatively low temperature, and in addition to this water inlet I also provide graduated hot water inlets 13 at difierent points along the same. The direction of the flow of the pulp is opposite to that of the water, in both legs of the apparatus, the water flowing from the inlets 14 and 13 to the outlet 17, and the pulp flowing from the inlet at the top of the vertical leg to the'outlet or discharge at the outer end of the inclined leg or cylinder. The inclination of the latter may be varied, as it may be horizontal or otherwise.

The trough is surrounded by a steam jacket 9 which is divided by partitions 10 into several sections each of which has a steam inlet 11 and a condensation outlet 12. The vertical leg at is also jacketed, and the various sections are heated to different temperatures, the highest temperature being around the vertical leg, and the lowest at the discharging end for the pulp. The trough is closed at the top by lids 3.0 clamped by any suitable means. The inclination of the trough and the height of the casing is such that the point of pulp discharge is higher than the cutlet 17, so that discharge of the juice is efiected by overflow thereof through said outlet. In order to prevent a too rapid flow of water in the trough, the exterior of the cylinder 8 may be provided with a screw blade furnishing an obstruction to the flow oi": the liquid outside the perforated cylinder in the trough, and tending to force the same into the interior thereof, and at the same time conveying small solid particles which may pass through the openings in the cylinder to the outlet end for the pulp.

The rate or extent of the diffusion may vbe adjusted by varying the amount of water delivered, the amount of material acted on in a certain time, and the rapidity of rotation of the conveyer, as Well as the temperatures employed.

In the pertormance of the process the pulp or material is fed into the vertical leg and to the .conveyer, and water is flowed in the contrary direction from the various Water inlets to the outlet for the juice, the requisite heat being supplied to the jackets. Preferably the pulp feed is so regulated that the cylinder 8 is only partly filled, and by its rotation the material is tumbled or lifted and dropped during its discharge through the cylinder, whereby all the parts of the pulp are exposed to the water which extracts the sugar content by solution, the juice increasing in density as the operation proceeds. The constant agitation of the mate rial, loosely inclosed in a rotary chamber, gives a much better extraction than when a packed mass is forced through a fixed container, as with the former apparatus, the material being continually agitated and caused to travel in a state of partial suspension in the extracting liquid.

What I .claim is:

1. A continuous diflfusion process comprising passing disintegrated material in one direction through an elongated container, rotating said container to tumble the material therein, and flowing water through said material in the container in another direction.

2. A d-i fi' usion process comprising passing disintegrated material in one direction through an elongated perforated container in a stream insuflicient to 11 said container, agitating the material in the container as it is passed through the same, and flowing water through said material "in the container in the opposite direction.

3. A continuous .difiusion process comprising passing a stream of pulp in. one direction through a perforated container submerged in .a body of extracting liquid flowing in another direction and agitating the material as it passes through the container.

4. A continuous diffusion process comprising passing a stream of pulp one direction vthrough a perforated container submerged in a body cit heated water flowing in th opposite direction, and rotating the container to tumble the pulp therein as it passes therethrough.

In testimony whereof, I aiiix my signature in presence of two witnesses.

JOHN STERVART.

Witnesses:

PERCY SHELLY, F. .O. NELSON.

Copies 0! this patent may be obtained for five cents each, by addressing @the Commissioner 0! Eaten. Washington, D. G." 

